10 Vascular occlusions and myopathies Flashcards
Risk factors for hypertensive retinopathy:
> 40 yo
Stroke (related to cotton wool spots)
Heart failure
Brain damage
Renal failure
Ocular diseases related to hypertension
Retinal vein/artery occlusion
Ischaemic optic neuropathy
Progression of diabetic retinopathy
Glaucoma
AMD
Pathophysiology of ocular hypertension:
Rising BP > vasospasm > retinal artery narrowing > hyperplasia (copper wiring) > venule compression (nipping)
BRB breakdown > haemorrhaging / lipid (hard) exudates > nerve ischemia (cotton wool spot) > disc oedema
Stages of hypertensive retinopathy:
Mild: artery narrowing/coppering/nipping
Moderate: flame/blot haemorrhage, lipid exudate, cotton wool spot, microaneurysms
Severe: Disc oedema (papilloedema)
Hypertensive retinopathy management:
Mild: routine care
Moderate: Daily BP monitor
Severe: antihypertensive care
Treated via angiotension-converting enzyme (ACE) inhibitors
Retinal vein occlusion presentation
Dilated / tortuous veins with haemorrhages, cotton wool spots, macula/disk oedema.
Either central (whole retina affected), or branch (sectioned away from disc)
Retinal vein occlusion risks
Hypertension (5x likely)
Diabetes
Stroke
Smoking
Retinal vein occlusion complications:
Neovascularisation
Macula oedema
Retinal emboli presentation:
Small discoloured lesions in lumen of arterioles
Cholesterol crystals > reflective emboli (white)
Calcium/fibrin > non-reflective emboli
Retinal emboli epidemiology:
1.5% incidence >40yo
Asymptomatic emboli > 90% self resolved in 5 years
Retinal emboli risk factors
Hypertension
Diabetes
Smoking
Retinal emboli causes and treatment
Plaque breakoff from large artery (carotid)
Treated via anticoagulants
Central retinal artery occlusion clinical presentation:
Sudden painless unilateral loss of vision
Whitening of retina with red macula (cherry red spot)
Branch retinal artery occlusion clinical presentation
Visual field defect
Present with emboli
CRAO treatment:
Embolus dislodgment via eye massage, IOP decrease, bag hyperventilation (CO2 induced vasodilation)
Retinal macroaneurysm:
Hypertension related artery rupture
Permeant vision loss with partial recovery with thrombosis of macroaneurysm
Ischemic optic neuropathy epidemiology
Most common neuropathy >50yo
Mostly anterior optic nerve ischemia
Ant. Is either arteritic (artery inflammation) / non-arteritic (HT/DB related)
Ischemic optic neuropathy presentation
Sudden vision loss
Ant. Ischemia > disc oedema
Pos. Ischemia > no disc oedema
Diabetic retinopathy epidemiology:
1/3 diabetics at 40yo
Hypertension (high bp) increases progression with type-1 DB
Type-2 DB is unrelated to HT
Diabetic retinopathy pathophysiology:
Hyperglycaemia > microaneuryms > vessel occlusion > retinal ischemia > VEGF increase > neovascularisation
Diabetic retinopathy treatment:
Beta blocker (atenolol) decreases BP below 125mmHg
Angiotensin converting enzyme (ACE) inhibitors treat type-1 DB
Glaucoma related to hypertension pathophysiology:
Vascular damage > poor Ant. ON circulation
Ciliary circulation interference > poor Aque. Flow
Causes of epiretinal membrane
Idiopathic (most common)
Surgery/trauma
Diabetic retinopathy
Vein occlusion
Macula oedema
Retinal detachment
Age
Epiretinal membrane epidemiology
Incidence increases >50yo
20% 75yo
Epiretinal membrane pathophysiology:
Ageing vitreous > liquification > Posterior vitreous detachment (PVD) > dehiscence in internal limiting membrane > microglial cell migration to preretinal surface > microglial interaction with hyalocytes/laminocytes > differentiation to epiretinal membrane
Epiretinal membrane symptoms:
Asymptomatic (most common)
Metamorphopsia, photopsia, blur, floaters
Epiretinal membrane classification:
Cellophane macular reflex: asymptomatic thin reflective membrane
Preretinal macular fibrosis: cellophane thickening / contraction > retinal folds, macula hole, metamorphopsia
Management of epiretinal membrane:
pars-plana vitrectomy with ERM/ILM peel with dye (Trypan/Brilliant Blue, Indocyanine Green)
Must be combined with cataract surgery
Epiretinal membrane complications:
Cataracts
Retinal detachment/break
Macula hole
Retinal haemorrhage
Endophthalmitis
